I find this article very insightful. He makes the case that as a culture we expect children to learn by doing in sports (which we understand), and yet are terrified of the smaller risks involved in hands-on science education (since we don't understand why chemicals go "Boom!", or even what that means).:

[...]But no one who has heard an oxy-hydrogen soap bubble explode in a lecture hall can ever doubt the value of stoichiometric calculations. Do you believe that the Apollo moon rocket ran on diesel fuel, just like a truck? I can show you an experiment that will make you believe it could as easily have run on bacon.

Teachers should be able to do this kind of science, and many would love to, but cannot because of the fear of what would happen if there were ever an accident. A student suffering even a relatively minor injury from a dangerous chemical would be front page news anywhere in the U.S., even if the same student spending a week in the hospital due to a sports injury would go completely unnoticed (unless perhaps he's the star quarterback).

The science teacher would likely lose their job, while the coach would be offered condolences on the loss of their star player.

The same dynamic show's up even between different sports. When I was in highschool my gym teacher taught us Australian rules football and everyone enjoyed it. We played it a lot until someone was injured, a minor ankle sprain. After that the administration decided it was too dangerous and banned it. Literally the next day someone fractured their skull playing softball (they were hit in the head with a very hard line drive) and no one said a word about banning softball.

Basically we accept the dangers associated with things we are familiar with.

I noticed some of this when reading Uncle Tungsten: Memories of a Chemical Boyhood by Oliver Sacks. He tells a lot about being to go to the chemists and simply buy whichever chemicals he wanted and experiment however he liked, at (my memory may be failing me here) age ten or so.

It seems like some things have become less familiar, as chemistry sets used to be a popular present for children.